Effect of intravenous administration of corticosteroids on dentin formation in the adult rat molar

Abstract

Nasstrom K, Petersson A, Konrad P: Effect of intravenous administration of corticosteroids on dentin formation in the adult rat molar. Scand J Dent Res 1989; 97: 301-6.Abstract -This study describes the effects of intravenously given corticosteroids on dentin formation in adult rat molars. Six rats twice a day received corticosteroids 20 mg/kg for 8 days, 10 mg/kg for 13 d.ays, and 5 mg/kg for 19 days. Six rats given a heterotopic heart transplant received 10 mg/kg of corticosteroids twice a day for 40-64 days. Six rats were used as controls. Tetracycline was given at the start .of ±e experiment and after 3 wk of treatment. After 40-46 days the rats were killed. Light microscopic examination of the molars showed no differences in the dentin formation or in the predentin zone between the experimental and control rats. In the ultraviolet light microscope two lines of tetracycline were visible along the root canal walls in both experimental groups. There was an obvious distance between the two lines, which indicated formation of new dentin. In the control grotip no formation of dentin was visible.

Effect of Long-term Corticosteroids on Dental Pulp

“…10 mature odontoblasts show a different reaction pattern to the altered hormone level and thus start forming new dentin. 5 Long-term administration of corticosteroids has complex actions which exerts great effect on odontoblasts. The mature odontoblast shows a different reaction pattern to the altered hormonal levels, but subsequent continuous dentin deposition is seen.…”

“…3,4 The formation of dentin has been ascribed to medication with high doses of corticosteroids. 5 Excessive formation of bone like substances and disorganized odontoblasts in pulp chamber is seen in histological sections. 6 The width of the predentin zone could be approximately four times greater than in normal teeth and extensive formation of secondary dentin could be seen in some cases.…”

Dental Pulp Changes Observed in a Patient on Long-term Corticosteroids

“…Whether there is a difference in blood flow or a difference in odontoblast response between the anterior teeth and molars is unknown. In studies using PL-pretreated rats, Anneroth et al 3) observed definite bone-like tissues in the incisors, and Näsström et al 9) demonstrated gradual calcification of molars by tetracycline labeling. Their findings may suggest that the dental pulp changes in the molars may take time to develop.…”

Untitled

“…Other authors established that pulp calcification occurs because of necrosis of the outer pulp layer without disturbance of normal production of dentin in condition of prolonged application of corticosteroids [13]. The initiation of new dentin layers formation is related to fluctuations of steroid hormones and modified functional activities of mature odontoblasts [8]. These cells of the periphery topographic zone of the pulp tissue complex are characterized with specific sample of reaction to the dynamic variations of steroid hormones, not afflicting regular deposition of dentin [14].…”

“…Researchers have reported conditions of considerable dilatation of blood vessels into the pulp vascular plexus [6,7]. Corticosteroids give impact upon the process of tertiary dentin synthesis and secretion [8]. In histological slides can be observed zones of disturbed odontoblasts in the region of coronal and radicular pulp chamber [9].…”